Take 'em off the network, docs told, until 2015 patches arrive

Hackers can exploit trivial flaws in network-connected Siemens' medical scanners to run arbitrary malicious code on the equipment.

These remotely accessible vulnerabilities lurk in all of Siemens' positron emission tomography and computed tomography (PET-CT) scanners running Microsoft Windows 7. These are the molecular imaging gizmos used to detect tumors, look for signs of brain disease, and so on, in people. They pick up gamma rays from radioactive tracers injected into patients, and perform X-ray scans of bodies.

US Homeland Security warned on Thursday that exploits for bugs in the equipment's software are in the wild, and "an attacker with a low skill would be able to exploit these vulnerabilities." That's because the flaws lie within Microsoft and Persistent Systems' code, which runs on the Siemens hardware, and were patched years ago.

The patches just didn't make their way to the scanners. That means an attacker on, say, a hospital network could access the machines and hijack them, or from afar over the internet if the device isn't properly secured and left facing the public web.

"Siemens is preparing updates for the affected products. These vulnerabilities could be exploited remotely. Exploits that target these vulnerabilities are known to be publicly available."

The flaws are:

CVE-2015-1635: Patched by Microsoft in its web server code in 2015. A specially crafted request can be sent to port 80 or 443 by an unauthenticated miscreant to either crash the service – a ping of death, effectively – or execute arbitrary code within the kernel and commandeer the machine. The affected Siemens equipment uses this web server to provide a user interface over the network.

CVE-2015-1497: Patched by Persistent Systems in its HP Client Automation service, which it licensed from HP in 2013 and now maintains and distributes itself. The bug was fixed in 2015. The software is known these days as Radia Client Automation software. The code is bundled with affected Siemens equipment for remote administration. The vulnerability can be exploited by an unauthenticated remote attacker to execute arbitrary code by sending a specially crafted request to port 3465.

CVE-2015-7860, CVE-2015-7861: More remotelyexploitable bugs in the HP, er, Radia automation service, all patched in 2015.

"Siemens is preparing updates for the affected products and recommends protecting network access to the molecular imaging products with appropriate mechanisms," ICS-CERT added. "It is advised to run the devices in a dedicated network segment and protected IT environment."

You can find an advisory from Siemens here on what to do next if you're an administrator for one of these machines. If you can't patch immediately, you're basically told to unplug them from the network. They are perfectly capable of being run in standalone mode, apparently.

Which is good, because no one wants an X-ray scanner to go nuts at the hand of a hacker while a patient is in it. ®